I think you're right. According to [0], and why would you need any other source for such things, a modern chest X-ray is about 20 µSv. Your two feet combined a

I think you're right. According to [0], and why would you need any other source for such things, a modern chest X-ray is about 20 µSv. Your two feet combined are smaller than your chest, and in a safer place for radiation, but let's call it the same conservatively. From the same source, a 4,000-km cross-country flight is 40 µSv. We allow airline workers and other business travellers to rack up a couple of hundred of those a year without worrying too much, so it should be safe to try on at least dozens of pairs of shoes per year. In practice, we'd surely demand too much regulatory burden for this tech to ever make it back to shoe stores. If shoe salesmen have to be as qualified, regulated and insured as radiologists, it would be cheaper to make custom shoes. [0] https://xkcd.com/radiation/ https://xkcd.com/radiation/